A study presented at the Experimental Biology 2014 conference shows that consuming tart cherry juice in the morning and evening may help you sleep better at night.
Researchers from Louisiana State University found that drinking Montmorency tart cherry juice twice a day for two weeks helped increase sleep time among older adults with insomnia.For the randomized crossover clinical trial, seven older adults (average age 68) with insomnia consumed 8 oz of tart cherry juice twice daily for two weeks, followed by a two-week washout period, then a two-week period when another beverage was consumed (placebo). The researchers studied the participants' slumber in a controlled setting, using overnight polysomnography to evaluate sleep efficiency, such as sleep onset and duration. Participants also completed questionnaires related to sleep, fatigue, depression, and anxiety. Additionally, blood work was conducted on each participant.
The researchers found that those who drank the Montmorency tart cherry juice in the morning and at night were able to sleep more than an hour longer each night (averaging 84 min) compared to the placebo, and their sleep tended to be more efficient.
Montmorency tart cherries are a natural source of melatonin, a hormone that helps regulate the sleep-wake cycle. The researchers believe the red pigments in tart cherry juice, known as proanthocyanidins, also play a role. These natural polyphenolic compounds are especially abundant in Montmorency tart cherries. In the study, tart cherry juice helped to increase the availability of tryptophan, an essential amino acid and a precursor to serotonin that helps with sleep. The juice was shown in cells to inhibit an enzyme (indoleamine 2,3 dioxygenase) that degrades tryptophan. Tryptophan degradation is a known predictor of insomnia and is also related to inflammation.
The researchers believe it's the unique combination of melatonin and tryptophan in Montmorency tart cherries that is likely contributing to the sleep benefits. They concluded that drinking a glass of tart cherry juice in the morning and the evening may be a better and a safer way to treat insomnia.